8th Grade Teaching Materials for NGSS

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Mystery Mix (Day 3)

A mysterious mixture… made from two of nine white substances… “Mr. A, that’s 72 different combinations of chemicals. We’re never going to be able to test them all!”

You don’t have to! Using yesterday’s observations, students selected combinations of chemicals that they thought looked similar to what they had observed in the Mystery Mix. Then, using a well tray and a small bottle of water, they did several reaction tests. They were looking for fizzing, a sign of a chemical reaction, just like what occurred in the Mystery Mix.

However, there was one problem. Several of the combinations fizzed. In total, students were able to find seven different pairs of chemicals that produced a reaction. So how do we know which one it is? Observation will only get you so far; several of the pairs reacted in similar ways. So tomorrow, on the final day of the experiment, we will add one more tool… an apparatus that will help us solve the mystery once and for all!